CVE-2024-8158CWE-639

User impersonation for lib9p based 9p fileservers

High · published August 25, 2024

CVSS v4.0
8.8
EPSS
0%
Percentile
30.4
In the wild
Unconfirmed
What it is

A bug in the 9p authentication implementation within lib9p allows an attacker with an existing valid user within the configured auth server to impersonate any other valid filesystem user.

This is due to lib9p not properly verifying that the uname given in the Tauth and Tattach 9p messages matches the client UID returned from the factotum authentication handshake.

The only filesystem making use of these functions within the base 9front systems is the experimental hjfs disk filesystem, other disk filesystems (cwfs and gefs) are not affected by this bug.

This bug was inherited from Plan 9 and is present in all versions of 9front and is remedied fully in commit 9645ae07eb66a59015e3e118d0024790c37400da.

The record
Technical detail
CVSS v4.0
8.8 · HIGH
Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/AU:N/V:C/RE:L/U:Red
EPSS
0.00376 · 30.4th percentile
Weakness
CWE-639 · Authorization Bypass Through User-Controlled Key
Published
2024-08-25T21:31Z
EPSS history
Timeline
  • 25 AUG 21:31Z
    User impersonation for lib9p based 9p fileservers
    cvelistv5